Which metering devices are designed without any adjustable features?

Which metering devices are designed without any adjustable features?

• A. Expansion valve and capillary tube
• B. Orifice plate and expansion valve
• C. Capillary tube and orifice plate
• D. Thermostatic expansion valve and float valve

Answer: (C)

The choice indicating that capillary tubes and orifice plates are designed without adjustable features is accurate because both devices serve specific functions in fluid systems without the ability to alter their performance through adjustments. Capillary tubes are fixed-diameter tubes that allow gas or liquid to flow based on pressure differences. Their primary function is to regulate refrigerant flow in refrigeration systems and they do this passively, without any components that can be adjusted. This means their capacity to control flow rates is inherently defined by their physical dimensions. Orifice plates operate similarly, functioning as fixed restrictions within a pipeline. They create a pressure drop and regulate flow, but do not possess any adjustable mechanisms. The size and shape of the orifice determine the flow characteristics, and once installed, these plates cannot be modified for flow adjustments. In contrast, items like the expansion valve and thermostatic expansion valve have adjustable features to allow operators to control refrigerant flow based on system demands. The float valve, used in various applications for level control, also generally features an adjustable element to maintain specific liquid levels. Thus, the focus on capillary tubes and orifice plates highlights their design as inherently fixed devices, making them unique in their function by lacking any adjustable components.

The choice indicating that capillary tubes and orifice plates are designed without adjustable features is accurate because both devices serve specific functions in fluid systems without the ability to alter their performance through adjustments.

Capillary tubes are fixed-diameter tubes that allow gas or liquid to flow based on pressure differences. Their primary function is to regulate refrigerant flow in refrigeration systems and they do this passively, without any components that can be adjusted. This means their capacity to control flow rates is inherently defined by their physical dimensions.

Orifice plates operate similarly, functioning as fixed restrictions within a pipeline. They create a pressure drop and regulate flow, but do not possess any adjustable mechanisms. The size and shape of the orifice determine the flow characteristics, and once installed, these plates cannot be modified for flow adjustments.

In contrast, items like the expansion valve and thermostatic expansion valve have adjustable features to allow operators to control refrigerant flow based on system demands. The float valve, used in various applications for level control, also generally features an adjustable element to maintain specific liquid levels.

Thus, the focus on capillary tubes and orifice plates highlights their design as inherently fixed devices, making them unique in their function by lacking any adjustable components.